Sen. Cory Booker, D-N.J. was a guest on CBS' "The Late Show" Tuesday night with Stephen Colbert. Well, it was early Wednesday by the time Booker's segment aired.

Colbert, who lives in Montclair, touched on some hot button issues with Booker from the midterm elections to the Supreme Court. And Booker dodged another question about whether he'll run for president in 2020.

Will Democrats block Supreme Court nominee?

Colbert asked Booker his thoughts on the Supreme Court after Republicans blocked President Barack Obama's nominee Merrick Garland in 2016 and whether Democrats might try the same tactic with President Donald Trump's pick Brett Kavanaugh.

"First of all, I don't think it's just the Democrats. I think all Americans have to decide. ... You shouldn't be silent in this moment because there's a lot is at stake. ... This is a moment that all of us should speak up," said Booker, noting that there was a time people thought the Affordable Care Act would be repealed until three Republican senators changed their vote.

"The die is not cast. ... Everyone who believes strongly about these issues should speak up because at the end the day the opposite of justice is not injustice. It is apathy. It's silence. This is a time when so much is at stake in your country that you have to speak up," Booker said.

Booker said he would meet with Kavanaugh because "that's the respectful thing to do."

Colbert pushed Booker for what he would want to ask the nominee.

Booker brought up Kavanaugh's 2009 opinion where he stated that "we should not burden a sitting president with civil suits, criminal investigations, or criminal prosecution."

Booker said, "I really want to know. ... Is this nominee going to make a commitment to recuse himself from all the matters of dealing with the Mueller investigation?"

“This is the probably most important midterm election of my lifetime in terms of giving a check or a balance to a president right now who has control of the House and Senate.” @CoryBooker#LSSCpic.twitter.com/cSHmfC5bhT

Midterm elections?

Colbert asked for Booker's predictions for the upcoming midterm elections. Booker avoided making any prognostications.

"This is a time for America to participate. The midterms often have very low voter turnouts," said Booker, who said he missed Obama, then joked, "I miss her husband too."

"I don't know what the outcome of the elections are going be, but it will be a great outcome if people vote, if people organize, if people knock on doors, if people let their voices be heard," Booker said.

Booker in 2020?

Colbert asked Booker if he would run in 2020, alluding to the presidential election.

"I will let you off the hook," Colbert said, "and let you know you are running."

Booker quickly countered.

"I am up for re-election as a United States senator in 2020, so I will be running in 2020."

Booker's a Dungeons and Dragons fan

Booker tried to joke with Colbert as he started his appearance, saying that one way he was hoping to bridge the gap between the Democrats and Republicans was to get a Dungeons and Dragons game in Congress. D&D is a popular fantasy tabletop role-playing game.

"I am always looking for things to do to cross the aisle. ... I am going to try to get a D&D game going in the Senate," joked Booker, who said he grew up playing the game. "I am going to make a proposal, go to Orin Hatch, go to Bernie Sanders and maybe I can get a great game going."